The Horse's Mouth

In the case of the present unpleasantness in Japan, that would be (what else?) the Bulletin of the Atomic Scientists. They have conveniently posted links to all of their Fukushima coverage on one page.

These are people who know what the heck they are talking about, think rigorously, write in a cautious and dispassionate voice, and are seeking the truth, not setting out to prove a preconceived conclusion. They don't necessarily come into this as nuclear power abolitionists, but they are all realists. And one reality is that government and industry have been relentlessly lying to the people about radiation safety since the Manhattan Project. Here's Barbara Rose Johnston:

During the Cold War, scientific findings on health effects to nuclear fallout that contradicted the official narrative were typically censored. Scientists were not only punished for their work, they were also blacklisted -- one example of this was American anthropologist Earle Reynolds whose work for the Atomic Bomb Casualty Commission was censored in 1953 by the US government. His research showed that Japanese children who were exposed to fallout were not only smaller than their counterparts, but had less resistance to disease in general and were more susceptible to cancer, especially leukemia. The consequences of this censored history was examined in 1994 by the US Advisory Commission on Human Radiation Experimentation, which concluded that the radiation health literature of the Cold War years was a heavily sanitized and scripted version meant to reassure and pacify public protests while achieving military and economic agendas.

She notes that the "hydrogen gas" TEPCO reported venting from the damaged reactors in fact included radioactive tritium.

There are many other strong essays there. If you want to understand these issues better -- the Fukushima situation specifically, and the broader issues surrounding nuclear power -- check it out.